HZB Newsroom

Sear results - Keyword: quantum materials

  • <p>Dr. Felix B&uuml;ttner is leading a Helmholtz Young Investigator group at HZB on topological solitons.</p>
    Walter-Schottky-Award for Felix Büttner
    The Walter Schottky Prize honours outstanding work by young physicists in solid-state research. For 2022, the award goes to HZB physicist Dr Felix Büttner for his groundbreaking achievements in the field of magnetic skyrmions.

  • <p>Illustration of the QFI calculation&nbsp;&#8203;</p>
    Science Highlight
    Neutron data help to reveal “spooky” entanglement in quantum magnets
    Using data from the British neutron source ISIS from the year 2000, research teams have now demonstrated the viability of a “quantum entanglement witness” capable of proving the presence of entanglement between magnetic particles, or spins, in a quantum material. A team from HZB led by Prof. Bella Lake was also involved in the analysis.
  • News
    20 Years Russian-German Joint Laboratory at BESSY II
    To mark its 20th anniversary, the Russian-German Laboratory at the BESSY II storage ring for synchrotron radiation in Berlin is organising an online workshop on 18 and 19 November. Scientists will discuss the future perspectives of Russian-German cooperation as well as innovative projects and new goals of the laboratory.

  • <p>STM topography of a monolayer CrCl<sub>3</sub> grown on Graphene/6H-SiC(0001). Inset, a magnified topography image, which reveals the grain boundaries.</p>
    Science Highlight
    Spintronics: Exotic ferromagnetic order in two-dimensions
    An international team has detected at HZB's vector magnet facility VEKMAG an unusual ferromagnetic property in a two-dimensional system, known as “easy-plane anisotropy”. This could foster new energy efficient information technologies based on spintronics for data storage, among other things. The team has published its results in the renowned journal Science.

  • <p></p> <p>The picture shows the glowing filament which keeps the sample at constant temperatures during the measurements.</p> <p></p>
    Science Highlight
    Ultrafast magnetism: heating magnets, freezing time
    Magnetic solids can be demagnetized quickly with a short laser pulse, and there are already so-called HAMR (Heat Assisted Magnetic Recording) memories on the market that function according to this principle. However, the microscopic mechanisms of ultrafast demagnetization remain unclear. Now, a team at HZB has developed a new method at BESSY II to quantify one of these mechanisms and applied it to the rare-earth element Gadolinium, whose magnetic properties are caused by electrons on both the 4f and the 5d shells. This study is completing a series of experiments done by the team on Nickel, Iron-Nickel Alloys. Understanding these mechanisms is useful for developing ultrafast data storage devices.

  • <p>Map obtained for a thin barium titanate film after clustering the data measured by contact Kelvin probe force microscopy (cKPFM) by a machine learning method. From this map, scientists can obtain detailed information on how the ferroelectric domains are distributed and what their respective polarization amplitude is.</p>
    Science Highlight
    A sharp look into tiny ferroelectric crystals
    What happens to ferroelectric materials when their dimensions are greatly reduced? A team of researchers at HZB has now been able to show how this question can be answered in a detailed way.

  • <p>The Dirac cone is typical for topological insulators and is practically unchanged on all 6 images (ARPES measurements at BESSY II). The blue arrow additionally shows the valence electrons in the volume. The synchrotron light probes both and can thus distinguish the Dirac cone at the surface (electrically conducting) from the three-dimensional volume (insulating).</p>
    Science Highlight
    Disorder brings out quantum physical talents
    Quantum effects are most noticeable at extremely low temperatures, which limits their usefulness for technical applications. Thin films of MnSb2Te4, however, show new talents due to a small excess of manganese. Apparently, the resulting disorder provides spectacular properties: The material proves to be a topological insulator and is ferromagnetic up to comparatively high temperatures of 50 Kelvin, measurements at BESSY II show.  This makes this class of material suitable for quantum bits, but also for spintronics in general or applications in high-precision metrology.

  • <p></p> <p>Resonant X-ray excitation (purple) core excites the oxygen atom within a H<sub>2</sub>O molecule. This causes ultrafast proton dynamics. The electronic ground state potential surface (bottom) and the bond dynamics is captured by distinct spectral features in resonant inelastic X-ray scattering (right).</p> <p></p> <p></p>
    Review: X-ray scattering methods with synchrotron radiation
    Synchrotron light sources provide brilliant light with a focus on the X-ray region and have enormously expanded the possibilities for characterising materials. In the Reviews of Modern Physics, an international team now gives an overview of elastic and inelastic X-ray scattering processes, explains the theoretical background and sheds light on what insights these methods provide in physics, chemistry as well as bio- and energy related themes.

  • <p>The development of this speckle pattern over time reveals microsocopic fluctuations in the material.</p>
    Science Highlight
    When vibrations increase on cooling: Anti-freezing observed
    An international team has observed an amazing phenomenon in a nickel oxide material during cooling: Instead of freezing, certain fluctuations actually increase as the temperature drops. Nickel oxide is a model system that is structurally similar to high-temperature superconductors. The experiment shows once again that the behaviour of this class of materials still holds surprises.

  • <p>After about 5 seconds, a thin film of metallic water has formed around the NaK drop, recognisable by the golden shimmer.</p>
    Science Highlight
    Water as a metal - detected at BESSY II
    Under normal conditions, pure water is an almost perfect insulator. Water only develops metallic properties under extreme pressure, such as exists deep inside of large planets. Now, an international collaboration has used a completely different approach to produce metallic water and documented the phase transition at BESSY II. The study is published now in Nature.

  • <p>Snapshots of the electronic structure of Sb acquired with femtosecond time-resolution. Note the changing spectral weight above the Fermi energy (E<sub>F</sub>).</p>
    Science Highlight
    Future information technologies: Topological materials for ultrafast spintronics
    A team led by HZB physicist Dr. Jaime Sánchez-Barriga has gained new insights into the ultrafast response of topological states of matter to femtosecond laser excitation. Using time- and spin-resolved methods at BESSY II, the physicists explored how, after optical excitation, the complex interplay in the behavior of excited electrons in the bulk and on the surface results in unusual spin dynamics. The work is an important step on the way to spintronic devices based on topological materials for ultrafast information processing.

  • <p>The illustration shows two quantum dots "communicating" with each other by exchanging light.</p>
    Science Highlight
    How quantum dots can "talk" to each other

    A group at HZB has worked out theoretically how the communication between two quantum dots can be influenced with light.  The team led by Annika Bande also shows ways to control the transfer of information or energy from one quantum dot to another. To this end, the researchers calculated the electronic structure of two nanocrystals, which act as quantum dots. With the results, the movement of electrons in quantum dots can be simulated in real time.

  • <p></p> <p>Electron microscopy shows the graphene sample (gray) in which the helium beam has created a hole pattern so that the density varies periodically. This results in the superposition of vibrational modes and the emergence of a mechanical band gap. The frequency of this phononic system can be adjusted between 50 MHz and 217 MHz by mechanical tension.&nbsp;</p> <p></p>
    Science Highlight
    New skills of Graphene: Tunable lattice vibrations
    Technological innovation in the last century was mainly based on the control of electrons or photons. Now, in the emerging research field of phononics, phonons or vibrations of the crystal lattice attract attention. A team at Freie Universität Berlin and Helmholtz-Zentrum Berlin showed a graphene-based phononic crystal whose resonant frequency can be tuned over a broad range and has used a helium-ion microscope to produce such a crystal. This is a real breakthrough in the field of phononics, now published in Nano Letters.

  • Science Highlight
    World's first video recording of a space-time crystal
    A German-Polish research team has succeeded in creating a micrometer-sized space-time crystal consisting of magnons at room temperature. With the help of the scanning transmission X-ray microscope MAXYMUS at Bessy II at Helmholtz Zentrum Berlin, they were able to film the recurring periodic magnetization structure in a crystal. The research project was a collaboration between scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart, Germany, the Adam Mickiewicz University and the Polish Academy of Sciences in Poznań in Poland.

  • <p>The electronic structure of complex molecules can be assessed by the method of resonant inelastic X-ray scattering (RIXS) at BESSY II.</p>
    Science Highlight
    An efficient tool to link X-ray experiments and ab initio theory
    The electronic structure of complex molecules and their chemical reactivity can be assessed by the method of resonant inelastic X-ray scattering (RIXS) at BESSY II. However, the evaluation of RIXS data has so far required very long computing times. A team at BESSY II has now developed a new simulation method that greatly accelerates this evaluation. The results can even be calculated during the experiment. Guest users could use the procedure like a black box.

  • <p>The phonons distribution is complex (upper curves) and then simplifies with time to a Gaussian bell curve (lower curve).</p>
    Science Highlight
    How complex oscillations in a quantum system simplify with time
    With a clever experiment, physicists have shown that in a one-dimensional quantum system, the initially complex distribution of vibrations or phonons can change over time into a simple Gaussian bell curve. The experiment took place at the Vienna University of Technology, while the theoretical considerations were carried out by a joint research group from the Freie Universität Berlin and HZB.

  • <p>Ultracold atoms in an optical lattice have been considered for quantum simulation.</p>
    Science Highlight
    Modelling shows which quantum systems are suitable for quantum simulations
    A joint research group led by Prof. Jens Eisert of Freie Universität Berlin and Helmholtz-Zentrum Berlin (HZB) has shown a way to simulate the quantum physical properties of complex solid state systems. This is done with the help of complex solid state systems that can be studied experimentally. The study was published in the renowned journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).
  • <p>The participants after signing the cooperation agreement between IKZ and HZB in corona-conform distance: (from left to right) Dr. Andreas Popp (IKZ), Dr. Manuela Urban (FVB), Dr. Peter Gaal (IKZ), Prof. Dr. Catherine Dubourdieu (HZB), Prof. Dr. Thomas Schr&ouml;der (IKZ), Prof. Dr. Bernd Rech (HZB), Thomas Frederking (HZB).</p>
    HZB & IKZ bundle their competencies In crystalline energy and quantum materials
    On September 11, 2020, the Helmholtz-Zentrum Berlin (HZB) and the Leibniz-Institut für Kristallzüchtung (IKZ) signed a cooperation agreement to advance joint research on energy and quantum materials. As part of the cooperation, new types of X-ray optics for synchrotron radiation sources are also being developed.
  • <p>Structure of TUB75: the entire MOF architecture (top) and its conductive inorganic unit (bottom)</p>
    Science Highlight
    Molecular architecture: New class of materials for tomorrow's energy storage
    Researchers at the Technische Universität Berlin (TUB) have created a new family of semiconductors, the properties of which were investigated by the Helmholtz-Zentrum Berlin (HZB). The researchers christened the first member “TUB75”. The material belongs to the class called metal-organic frameworks, or MOFs for short, and could open up new opportunities for energy storage. The work was published in Advanced Materials.
  • <p>Intelligent mathematical tools for the simulation of spin systems reduce the computing time required on supercomputers. Some of the fastest supercomputers in the world are currently located at Forschungszentrum J&uuml;lich (shown here is JUWELS).</p>
    Science Highlight
    Mathematical tool helps calculate properties of quantum materials more quickly
    Many quantum materials have been nearly impossible to simulate mathematically because the computing time required is too long. Now a joint research group at Freie Universität Berlin and the Helmholtz-Zentrum Berlin (HZB) has demonstrated a way to considerably reduce the computing time. This could accelerate the development of materials for energy-efficient IT technologies of the future.

  • <p>This is how the experiment went: Two laser pulses hit the thin film of iron-platinum nanoparticles at short intervals: The first laser pulse destroys the spin order, while the second laser pulse excites the now unmagnetised sample. An X-ray pulse then determines how the lattice expands or contracts.</p>
    Science Highlight
    Robust high-performance data storage through magnetic anisotropy
    The latest generation of magnetic hard drives is made of magnetic thin films, which are invar materials. They allow extremely robust and high data storage density by local heating of ultrasmall nano-domains with a laser, so called heat assisted magnetic recording or HAMR. The volume in such invar materials hardly expands despite heating. A technologically relevant material for such HAMR data memories are thin films of iron-platinum nanograins. An international team led by the joint research group of Prof. Dr. Matias Bargheer at HZB and the University of Potsdam has now observed experimentally for the first time how a special spin-lattice interaction in these iron-platinum thin films cancels out the thermal expansion of the crystal lattice. The study has been published in Science Advances.

  • <p>At quantum physics atoms, molecules or photons are used to store information.</p>
    Science Highlight
    Benchmarking for quantum technologies
    Does a device do what it's supposed to? This question is not only asked in everyday life. Researchers working with quantum technologies also want to know what novel instruments can do. A team led by Prof. Jens Eisert, a physicist at the Dahlem Center for Complex Quantum Systems of Freie Universität Berlin and at Helmholtz-Zentrum Berlin, together with researchers from the Sorbonne University in Paris, have published an overview of tools that can currently be used to compare and certify quantum devices. The review article is published in Nature Reviews Physics.

  • <p>Two of the four magnetic interactions form a new three-dimensional network of corner-sharing triangles, known as the hyper-hyperkagome lattice, leading to the quantum spin liquid behavior in PbCuTe<sub>2</sub>O<sub>6</sub>.</p>
    Science Highlight
    Future information technologies: 3D Quantum Spin Liquid revealed
    Quantum Spin Liquids are candidates for potential use in future information technologies. So far, Quantum Spin Liquids have usually only been found in one or two dimensional magnetic systems only. Now an international team led by HZB scientists has investigated crystals of PbCuTe2O6 with neutron experiments at ISIS, NIST and ILL. They found spin liquid behaviour in 3D, due to a so called hyper hyperkagome lattice. The experimental data fit extremely well to theoretical simulations also done at HZB.
  • <p>Prof. Dr. Johannes Reuther works at the Freie Universit&auml;t Berlin and the HZB.</p>
    Freie Universität Berlin appointed Johannes Reuther as W2 professor

    On April 6, 2020 Freie Universität Berlin appointed Johannes Reuther to the joint W2 professorship "Theory of Novel Quantum Materials”. The physicist will conduct research at both Helmholtz-Zentrum Berlin (HZB) and Freie Universität Berlin. The joint appointment will build a bridge between experimental and theoretical physics.

  • <p>In HoAgGe, holmium spins occupy the corners of triangles that are arranged in a Kagome pattern. The alignment of adjacent spins (left, red arrows) must obey the ice rule: Either two spins protrude into a triangle and one protrude out, or vice versa. As a result the individual triangles behave as if they were magnetic monopoles (right).</p>
    Science Highlight
    Neutron research: Magnetic monopoles detected in Kagome spin ice systems
    Magnetic monopoles are actually impossible. At low temperatures, however, certain crystals can contain so-called quasi-particles that behave like magnetic monopoles. Now an international cooperation has proven that such monopoles also occur in a Kagome spin ice system. Decisive factors were, among others, measurements with inelastic neutron scattering at the NEAT instrument of the Berlin neutron source BER II*. The results have been published in the journal Science.
  • <p>In the ground state the magnetic moments are either upward or downward, the spins antiparallel to the external magnetic field (red) are never together (right). By excitation, further spins can align antiparallel and Bethe chains are formed (white spins, left).</p>
    Science Highlight
    Condensed Matter Physics: Long-standing prediction of quantum physics experimentally proven
    90 years ago, the physicist Hans Bethe postulated that unusual patterns, so-called Bethe strings, appear in certain magnetic solids. Now an international team has succeeded in experimentally detecting such Bethe strings for the first time. They used neutron scattering experiments at various neutron facilities including the unique high-field magnet of BER II* at HZB. The experimental data are in excellent agreement with the theoretical prediction of Bethe and prove once again the power of quantum physics.
  • <p>Felix B&uuml;ttner has set up a holography chamber at Brookhaven National Laboratory.</p>
    New Helmholtz Young Investigator Group at HZB
    Dr. Felix Büttner will establish a Helmholtz Young Investigator Group (YIG) on topological solitons at the HZB beginning in March 2020. Topological solitons occur in magnetic quantum materials and can contribute to extremely energy-efficient switching processes. Büttner wants to develop a new imaging technique at BESSY II to study these quasi-particles.
  • <p>Bei 25,8 Tesla findet in dem Urankristall ein Phasen&uuml;bergang statt und ein komplexes magnetisches Muster etabliert sich.</p>
    Science Highlight
    Not everything is ferromagnetic in high magnetic fields
    High magnetic fields have a potential to modify the microscopic arrangement of magnetic moments because they overcome interactions existing in zero field. Usually, high fields exceeding a certain critical value force the moments to align in the same direction as the field leading to ferromagnetic arrangement. However, a recent study showed that this is not always the case. The experiments took place at the high-field magnet at HZB's neutron source BER II, which generates a constant magnetic field of up to 26 Tesla. This is about 500,000 times stronger than the Earth's magnetic field. Further experiments with pulsed magnetic fields up to 45 Tesla were performed at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). 
  • Science Highlight
    Topological materials for information technology offer lossless transmission of signals
    New experiments with magnetically doped topological insulators at BESSY II have revealed possible ways of lossless signal transmission that involve a surprising self-organisation phenomenon. In the future, it might be possible to develop materials that display this phenomenon at room temperature and can be used as processing units in a quantum computer, for example. The study has been published in the renowned journal Nature.
  • <p>The Russian-German Laboratory operating its own beamline at BESSY II.</p>
    New instrument at BESSY II commences user operation
    A new instrument became available to the users of BESSY II on Oct. 28, 2019. The new beamline and apparatus for spin- and angular-resolved photoemission in the Russian-German Laboratory at BESSY II have successfully completed their test phase. They facilitate precise measurements of the electron band structure and spin of different material classes such as topological insulators and magnetic sandwich structures, as well as novel perovskite-based solar-cell materials. A photoelectron microscope has also been developed which is particularly important for nanoscopic structures.

  • Interview
    Joint research group for quantum computing and simulation
    Freie Universität Berlin and Helmholtz-Zentrum Berlin (HZB) are now strengthening their cooperation in the field of quantum computing with a new research group. Quantum materials exhibit very interesting properties, which researchers want to use to make data processing significantly faster and more efficient than is currently possible. They can study these materials excellently at synchrotron radiation sources such as BESSY II. It has proven especially promising to predict the material properties in quantum simulations before running the experiments. Taking this approach allows such experiments to be conducted more targetedly.
  • <p>The nano-antennae werde produced in an electron microscope by direct electron-beam writing.</p>
    Science Highlight
    Save time using maths: analytical tool designs corkscrew-shaped nano-antennae
    For the first time, an HZB team has derived analytically how corkscrew-shaped nano-antennas interact with light. The mathematical tool can be used to calculate the geometry that a nano-antenna must have for specific applications in sensor technology or information technology.
  • <p>When illuminated by the synchrotron light, nickel emits x-rays itself due to the decay of valence electrons. The number of emitted photons reduces when increasing the temperature from room temperature (left) to 900&deg;C (right).</p>
    Science Highlight
    Utrafast magnetism: electron-phonon interactions examined at BESSY II
    How fast can a magnet switch its orientation and what are the microscopic mechanisms at play ? These questions are of first importance for the development of data storage and computer chips. Now, an HZB team at BESSY II has for the first time been able to experimentally assess the principal microscopic process of ultra-fast magnetism. The methodology developed for this purpose can also be used to investigate interactions between spins and lattice oscillations in graphene, superconductors or other (quantum) materials.
  • <p>The illustration is alluding to the laser experiment in the background and shows the structure of TGCN.</p>
    Science Highlight
    Organic electronics: a new semiconductor in the carbon-nitride family
    Teams from Humboldt-Universität and the Helmholtz-Zentrum Berlin have explored a new material in the carbon-nitride family. Triazine-based graphitic carbon nitride (TGCN) is a semiconductor that should be highly suitable for applications in optoelectronics. Its structure is two-dimensional and reminiscent of graphene. Unlike graphene, however, the conductivity in the direction perpendicular to its 2D planes is 65 times higher than along the planes themselves.
  • <p>Experiments at the femtoslicing facility of BESSY II revealed the ultrafast angular momentum flow from Gd and Fe spins to the lattice via orbital moment during demagnetization of GdFe alloy.</p>
    Science Highlight
    Laser-driven Spin Dynamics in Ferrimagnets: How does the Angular Momentum flow?
    When exposed to intense laser pulses, the magnetization of a material can be manipulated very fast. Fundamentally, magnetization is connected to the angular momentum of the electrons in the material. A team of researchers led by scientists from the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (MBI) has now been able to follow the flow of angular momentum during ultrafast optical demagnetization in a ferrimagnetic iron-gadolinium alloy at the femtoslicing facility of BESSY II. Their results are helpful to understand the fundamental processes and their speed limits. The study is published in Physical Review Letters.
  • <p>The data show that In the case of the two-layer graphene, a flat part of bandstructure only 200 milli-electron volts below the Fermi energy.</p>
    Science Highlight
    Graphene on the way to superconductivity
    Scientists at HZB have found evidence that double layers of graphene have a property that may let them conduct current completely without resistance. They probed the bandstructure at BESSY II with extremely high resolution ARPES and could identify a flat area at a surprising location.
  • <p>Shown are the magnetic fluxlines inside a superconducting sample of lead in two different directions. The scale bar is 5 mm. </p>
    Science Highlight
    Neutrons scan magnetic fields inside samples
    With a newly developed neutron tomography technique, an HZB team has been able to map for the first time magnetic field lines inside materials at the BER II research reactor. Tensorial neutron tomography promises new insights into superconductors, battery electrodes, and other energy-related materials.
  • <p>Sketch of the stripe order: The charge stripes, which are superconducting, are shown in blue. Reprinted with modifications from Physical Review Letters.</p>
    Science Highlight
    User research at BER II: New insights into high-temperature superconductors
    After 30 years of research, there are still many unsolved puzzles about high-temperature superconductors - among them is the magnetic “stripe order” found in some cuprate superconductors. A Danish research team has taken a closer look at these stripes, using high-resolution neutron scattering at the spectrometers FLEXX (HZB) and ThALES (ILL, Grenoble). Their results, now published in Physical Review Letters, challenge the common understanding of stripe order, and may contribute to unveil the true nature  of high-temperature superconductivity.
  • <p>This optical zone melting furnace is producing large single crystals. </p>
    New at Campus Wannsee: CoreLab Quantum Materials
    Helmholtz-Zentrum Berlin has expanded its series of CoreLabs for energy materials research. In addition to the five established CoreLabs, it has now set up a CoreLab for Quantum Materials. A research team from the HZB Institute for Quantum Phenomena in New Materials is responsible for the CoreLab and its modern equipment. The CoreLab is also open to experimenters from other research institutes. 
  • <p>X-PEEM images show the orientation of magnetic domains in the permalloy film overlaid on the superconducting dot (dashed square) before (left image) and after the write process (right image). In this sample the domains (arrows, right image) are reorientied in a monopole pattern. </p>
    Science Highlight
    Future Information Technologies: New combinations of materials for producing magnetic monopoles
    An international collaboration at BESSY II has discovered a new method to inscribe exotic magnetic patterns such as magnetic monopoles into thin ferromagnetic films. Such unconventional orientation of magnetic domains might open a new path for the design of energy efficient data storage. The new materials system consists of regular arrays of superconducting YBaCuO-dots covered with an extremely thin permalloy film. A shortly applied external magnetic field leads to the creation of supercurrents within the superconducting dots. These currents produce a complex magnetic field pattern, which is inscribed into the permalloy film above. The results are published in Advanced Science.
  • <p><strong>Frostige Wissenschaften:</strong> Experimente mit fl&uuml;ssigem Stickstoff</p>
    Eine lange Nacht geballtes Wissen tanken
    Führungen an der Neutronenquelle, Experimente zur Energie für Groß und Klein, Licht-Show und vieles mehr
  • <p>Crystal structures of HgBa<sub>2</sub>CuO<sub>4</sub>+ and YBa<sub>2</sub>Cu<sub>3</sub>O<sub>6</sub>+</p>
    Science Highlight
    Universality of charge order in cuprate superconductors
    Charge order has been established in another class of cuprate superconductors, highlighting the importance of the phenomenon as a general property of these high-Tc materials.
  • <p>Aus dem Technikum</p>
    Hochfeldmagnet sucht Neutronenleiter
    Am Freitag, den 12. Dezember 2014 fand der Umzug des Hochfeldmagneten an seinen endgültigen Aufstellungsort in der Neutronenleiterhalle statt. Eine Spezialfirma für Maschinentransporte bugsierte den über 25 Tonnen schweren Stahlkoloss aus dem HFM-Technikum heraus und setzte ihn in Bewegung.
  • <p>Outstanding researchers took part in the &ldquo;New Trends in Topological Insulators 2014&rdquo; - workshop.</p>
    Leading scientists on topological insulators met in Berlin
    From July 7-10, 150 researchers met in Berlin to discuss recent findings in the field of topological insulators.
  • <p><span><span>Despite the onset of winter, the High-Field Magnet arrived in Berlin without difficulty. The magnet will be connected to the cooling facility, power supply, and the neutron guide over the next months. Photo: </span><span>HZB/Phil Dera</span></span></p>
    High-Field Magnet crossed the finish line at Helmholtz-Zentrum Berlin
    The High-Field Magnet (HFM) for diffracting neutrons entered the gates of the Helmholtz-Zentrum Berlin in Wannsee on 23 January 2014 at 9am, where the project team headed by Dr. Peter Smeibidl enthusiastically accepted delivery. The journey for the roughly 20-tonne scientific device began in the Italian city of Chivasso near Turin two days prior on 21 January. It traversed its 1200 kilometre route without incident, which led through Milan, the Gotthard Tunnel, Zürich, and Stuttgart to Berlin.
  • <p>Stripe order of charge carriers in Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>8+x</sub> [2]. The figure shows the structure with a period of approximately one nanometer (front) and the related diffraction pattern (back) obtained by a so-called Fourier transformation (Yazdani Lab, Princeton University).</p>
    Science Highlight
    Charge Order competes with superconductivity
    Today in Science Express: Charge carriers in cuprate high-Tc superconductors form nanostripes that suppress superconductivity, as shown by guest researchers from Princeton and Vancouver using synchrotron radiation at BESSY II
  • News
    High field magnet for neutron scattering has made its way to Italy
    After five years of manufacture, the superconducting spool for the new high field magnet for neutron scattering finally took off from Atlanta, USA, inside the belly of an MD-11F Lufthansa cargo plane on October 9, 2013, at 3:00 am EST. The plane landed in the cargo area at Frankfurt Airport promptly at 6:21 pm that same day. Following German customs clearance, the magnet was subsequently transferred to Italy by truck where, on Friday, October 11, it arrived in Chivasso/Turin.
  • HZB-Wissenschaftler Dr. Christian Schüßler-Langeheine
    Tiefer Röntgenblick zeigt: Supraleiter sind komplizierter als gedacht - Rätselhaft verschwindende Streifenstruktur
    Keramische Supraleiter sind komplizierter als gedacht. Das zeigt eine Untersuchung sogenannter Lanthan-Cuprate mit den Röntgenquellen BESSY II am Helmholtz-Zentrum Berlin (HZB) und DORIS III bei DESY in Hamburg. Die elektrischen Strukturen, die sich in dem Material ausbilden, können demnach in der Nähe der Oberfläche ganz anders sein als in der Tiefe. Dieses Wissen ist wichtig für das Verständnis der komplizierten Vorgänge in den widerstandsfreien Stromleitern und kann der Konstruktion neuer Supraleiter mit maßgeschneiderten Eigenschaften helfen. Allerdings bedeutet sie auch, dass eine Reihe von Untersuchungen unter Umständen ergänzt werden müssen, wie das internationale Team um HZB-Forscher Christian Schüßler-Langeheine im Fachjournal "Nature Communications" berichtet.
  • Künsterische Darstellung der Aufspaltung eines Elektrons<br />
    Physiker beobachten, wie ein Elektron im Festkörper in neuartige Quasiteilchen zerfällt
    Physiker eines internationalen Forschungsteams haben erstmals beobachtet, wie sich ein Elektron in zwei voneinander getrennte Teile aufspaltet, die jeweils eine bestimmte Eigenschaft des Elektrons tragen: Das sogenannte «Spinon» trägt dann den Spin des Elektrons, also seine Eigenrotation. Diese lässt das Elektron zu einer winzigen Kompassnadel werden. Das «Orbiton» ist der Träger des orbitalen Moments – das ist die Bewegung um den Atomkern. Diese neu hergestellten Teilchen können das Material, in dem sie erzeugt wurden, nicht verlassen. Justine Schlappa vom Helmholtz-Zentrum Berlin hat diese Ergebnisse jetzt zusammen mit ihren Kollegen in der Fachzeitschrift Nature veröffentlicht (DOI: 10.1038/nature10974). Die Ergebnisse wurden an der Synchrotronquelle SLS des schweizerischen Paul Scherrer Instituts erzielt, wo Justine Schlappa zu Beginn des Projekts beschäftigt war.
  • Abbildung der transversalen Ladungsverteilung auf einem<br />Leuchtschirm, der für die Messung in den Strahlengang des<br />Elektronenstrahls gefahren ist.
    Wichtiger Schritt Richtung BERLinPro: Erster Elektronenstrahl aus SRF Quellinjektor
    Am 21. April 2011 hat das HZB mit einer supraleitenden Elektronenquelle (SRF Gun) die ersten Photoelektronen erzeugt und beschleunigt. Dies ist ein Meilenstein für das Projekt BERLinPro, und es ist zugleich weltweit das erste Mal, dass mit einem supraleitenden Hochfrequenz-Photoinjektor aus einer supraleitenden Photokathode ein Elektronenstrahl erzeugt worden ist.
  • News
    New material provides a key to explaining superconductivity

    [Translate to Englisch:] Forscher des Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) stellen in der aktuellen Ausgabe der Zeitschrift Nature Materials neue Ergebnisse vor, die einen alten Streit um die richtige Theorie lösen könnten.

  • News
    More than 300 Scientists at SRF 2009 in Berlin
    International Conference on RF-Superconductivity and Accelerator Physics was a great success! 
  • Nachricht
    Orbital 2009 - internationaler Workshop am HZB
    Am 7. und 8. Oktober 2009 findet am Helmholtz-Zentrum Berlin am Standort Adlershof der Workshop "Orbital 2009" mit 95 Teilnehmern aus aller Welt statt.
  • Nachricht
    Supraleiter unter Druck gesetzt und damit Geheimnisse entlockt

    Wissenschaftler des Helmholtz-Zentrums Berlin für Materialien und Energie (HZB) gewinnen neue, überraschende Einblicke in das Phänomen der Supraleitung. In Kooperation mit mehreren internationalen Forschergruppen berichten sie dies in der aktuellen Ausgabe der Zeitschrift Nature Materials, die eine Online-Version als Highlight-Beitrag vorab veröffentlicht.

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<p>Auf dem Bild schwebt der Dipolmagnet &uuml;ber einem gek&uuml;hlten Supraleiter, ein aus Yttrium- Barium-Kupferoxid (YBCO) bestehender keramischer Stoff.</p>
    Dreidimensionale Bildgebung- erstmalige Einblicke in Magnetfelder
    3D-Bilder werden nicht nur in der Medizin erzeugt, etwa mithilfe der Röntgen- oder Kernspinresonanztomographie. Auch Materialwissenschaftler blicken gern ins Innere eines Körpers. Forschern des Berliner Hahn-Meitner-Instituts (HMI) ist es nun in Kooperation mit der Technischen Fachhochschule Berlin (TFH) erstmals gelungen, Magnetfelder im Inneren von massiven, nicht transparenten Materialien dreidimensional darzustellen. Das berichten Nikolay Kardjilov und Kollegen in der aktuellen Ausgabe der Zeitschrift Nature Physics, die eine Online-Version als Highlight-Beitrag in dieser Woche vorab veröffentlicht.
  • <p>Modell des Hochfeldmagneten im Ma&szlig;stab 1:5</p>
    Der weltweit stärkste Magnet für Neutronenexperimente wird in Berlin errichtet
    Der Kooperationsvertrag zwischen dem Hahn-Meitner-Institut Berlin (HMI) und dem National High Magnetic Field Laboratory (NHMFL) Tallahassee (Florida State University) zum Bau eines neuen Hochfeldmagneten ist unterzeichnet worden. Er wird der weltweit stärkste Magnet für Neutronenstreuexperimente. Von den Experimenten an dem Magneten erwarten Forscher neue Erkenntnisse zu Fragen aus der Physik, Chemie, Biologie und den Materialwissenschaften, unter anderem Beiträge zum Verständnis der Hochtemperatursupraleitung.
  • <p>Anordnung der Natriumatome im Natriumkobaltoxid, wenn 80% der verf&uuml;gbaren Natriumpl&auml;tze besetzt sind. Die Farben Rot und Blau entsprechen den zwei m&ouml;glichen Positionen der Natriumatome.</p>
    Nanomuster bringen Strom unter Kontrolle: Natriumkobaltoxid als perfektes Material für Laptop-Batterien, als Kühlmittel oder Supraleiter
    Regelmäßige Muster aus Natriumatomen mit Strukturen im Nanometerbereich machen Natriumkobaltoxid zu einem perfekten Material für Laptop-Batterien, effiziente Kühlmittel oder Supraleiter – das berichten Wissenschaftler des Berliner Hahn-Meitner-Instituts, des CEA-Forschungszentrums in Saclay bei Paris und der Universität Liverpool in der neuesten Ausgabe des Wissenschaftsmagazins Nature. Dabei bestimmt die genaue Anordnung der Natriumatome die Eigenschaften des Materials, wobei das jeweilige Natriummuster sehr empfindlich von der Dichte an Natriumatomen abhängt. Diese ist mit chemischen Methoden leicht veränderbar, und man kann so aus einem anfangs metallischen Material einen Isolator und dann einen Supraleiter machen. Man bringt dazu das Material in eine elektrochemische Zelle und ändert die Spannung.
  • Nachricht
    Bose-Einstein-Kondensat: Magnetfelder erzeugen ungewöhnlichen Materiezustand

    In einem Experiment am Hahn-Meitner-Institut in Berlin wurden zum ersten Mal die magnetischen Eigenschaften eines Kristalls für die Erzeugung eines Bose-Einstein-Kondensats genutzt. Dieser ungewöhnliche Materiezustand entstand, als der Kristall in ein starkes Magnetfeld von 14 Tesla gebracht wurde und konnte mit Hilfe von Neutronen aus dem Forschungsreaktor des Hahn-Meitner-Instituts nachgewiesen werden. Mit Magnetfeldern von bis zu 17 Tesla (mehr als das 200.000-fache des Erdmagnetfelds) bei Experimenten mit Neutronen stehen in Berlin weltweit einzigartige Forschungsmöglichkeiten zur Verfügung, die Voraussetzung für Erzeugung und Nachweis des Kondensats waren.